基于分段FFT的断路器故障诊断策略设计及应用

Design and Application of Fault Diagnosis Strategy for Circuit Breaker Based on Segmented FFT

换流站交流滤波器断路器是高压直流输电系统的重要组成部分,其内部故障的发生将直接影响直流输电系统的稳定运行。针对滤波器用断路器的故障诊断,提出了一种根据交流滤波器断路器的分合闸电流诊断断路器健康状态的高效在线监测方法。首先,分析了交流滤波器断路器分合闸电流的时域特征和频域特征;然后,利用基于分段随机快速傅里叶变换(fast Fourier transform,FFT)的断路器分合闸涌流频域分析方法,实现对故障信息的实时监测与判定;最后,基于灵州换流站750 kV交流滤波器场7632断路器C相故障录波数据,开展诊断策略有效性分析与验证,结合断路器拆解检查,验证了所提故障诊断策略的有效性,为换流站交流滤波器断路器故障的在线诊断提供了可靠的解决方法,具有良好的工程应用价值。

The circuit breaker of AC filter in converter station is an important part of HVDC system.The occurrence of internal faults will directly affect the stable operation of HVDC system.In view of the fault diagnosis of the circuit breaker for filter,an efficient online monitoring method was proposed to diagnose the health status of the circuit breaker according to the on-off current of the AC filter circuit breaker.Firstly,the time-domain and frequency-domain characteristics of the switching current in the AC filter circuit breaker were analyzed.Then,the frequency-domain analysis method of the inrush current in the circuit breaker opening and closing based on segmented random fast Fourier transform(FFT)was used to realize the real-time monitoring and judgment of the fault information;finally,based on the data of C phase fault recording for the 750 kV AC filter field 7632 circuit breaker in Lingzhou converter station,the validity analysis and verification of diagnosis strategy were carried out.Combined with the circuit breaker disassembly and inspection,the effectiveness of the fault diagnosis strategy proposed was verified.It provides a reliable solution for the on-line diagnosis of circuit breaker fault in AC filter in converter station,and has good engineering application value.